Mercury-meter.



Patented `May 30, 1911.

3 SHEETS-SHEET l.

fr A A l l l l A W. H. PRATT.

MERCURY METER.

APPLIOATION rILBD APB.9.1908.

Wbnesses: qfwwl W. H. PRATT.

MERCURY METER.

APPLICATION FILED 111111.11, 190B.

Patented My 30, 1911.

3 SHEETS-SHEET 2.

Wltr'lesses: Inventor;

m l Willlam H. Pratt.,

la@ @MM Patented May 30, 1911.

3 SHEETS-SHEET 3.

IVM/enter? W. H. PRATT.

MERCURY METER.

APPLICATION FILED APx.9.19oa. 993,872.

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lllllllllll Il!" Witnesses Wllllam H. Draht.,

TE STATES PATENT OFFICE.

WILLIAM H'. PRATT, OF LYNN. MASSACHUSETTS, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION F NEW. YORK.

MERCURY-METER.

Specification of Letters Patent.

Application filed April 9,1908. Serial No. 426,005.

yPatented May 30, 1911.

l of such meters that will make them reliable in their action and cheaper, which improvements are pointed out more particularly in the appended claims.

For afurther understanding of my invention reference may be had to the accompanying drawings, where- Figure 1 shows a' front view of my new meter with the cover removed and portions shown. in section, Fig. 2 is a side view of my' new meter, with a portion of the cover brel-Len away 1n order to show better the meter construction and certain portions shown in section, Fig. 3 is a section on line 3 3 of Fig. 1, Fig. 4 is a section on line f1 4.

` of Fig. 1, Fig. 5 is a section of a detail in construction taken alon the line 5 5 in Fig. 3, and Fig. 6 is a sect1on taken along the line 6 6 of Fig. 3.

1 is a base which supports the meter and y to which is attached the usual cover 2 by means of studs 3 and 4, which are attached at one end to the base and at the other end have butterfly nuts 5 and 6 coperating with them to retain the cover in place. Attached to the base are three supports, 7, 8 and 9, to which are attached clips 10, 11 and l2, which support the permanent magnet 13. Secured to` either pole of the magnet are pole pieces 14 and 15 shown in Fig. 4, which pole pieces have their interior faces bored out as segments of a cylinder and having their upper faces, 16 and 17, cut away in order to support a ring 18, shown in Fig. 6, and in dotted lines in Fig. 4 that rests upon them. This ring is attached to the ole pieces by suitable screws threading into holes 19 and 20, so that it shall be rigidly attached to the magnet.

Resting upon ring 18 and'free to revolve upon it, 1s a ring or flange 21, which is fastened by rivets 22 to a cup-shaped retaining member 23, which surrounds the meter armature and retains or holds the mercury in which the armature revolves. This retaining member has fastened to 'it by screws 24 and covering it an insulating member 25, to which is fastened by means of screws 26 a magnetic member 27, which substantially fills the interior of the retainin member, allowing suflicient space between 1t and the retaining member for the cup-shaped `armature 32 to revolve in mercury between them.

Attached to insulating member 25 are binding posts 28, 29, which serve as con-V ductors for leading the current to the meter armature, and which are so placed as to make contact with the mercury surrounding the meter armature at oints diametrically opposite and above t e armature, as

shown in Fig. 1. T he retaining member 23 i carries a lower bearing 30, upon which bears the lower end of the meter shaft 31.` This of the armature, and thus it will revolve more uniformly in the mercury-filled space between the retaining member and the magnetic member which substantially fills-it.,

The meter armature has slots 35 cut in its upper edges in order to direct the flow of current.

Referring now to Fig. 5, ring 18 has two lugs 36, into which fit screws 37, holding down L-shaped members 36', which L-shaped members are in frictional contact with flange 21, so that when screws 37 are screwed down, flange 21 cannot be made to revolve upon ring 18. Rigidly attached to insulating member 25, and hence to the retaining 'member 23 and member 27 is a handle, 59, bymeans of which these members and the conductors 28 and 29 may be displaced when screws 37 are loosened. The object of this device is to calibrate the meter, for normally conductors 28 and 29 are positioned in a plane parallel to the flux produced between the poles of the magnet, and hence give the maximum torque-producing position for leading the current into the armature. .If it is desired 'to calibrate the meter, or alter its torque, the retaining member with the conductors may be rotated between the poles of the magnet, substantially about the armature axis, and as the position of the plane of the conductors differs from the normal position, so will the -meter torque be decreased proportionally.

the mercury uponsthe Imeterarmature','and- '46 has two flanges, 49 and 50, Within which f drawal. of nut 55 and acts as a stop when member 54 is in its lowest position. Nut 55 has a Vslot formed I portion of member 27, shown in Fig. 1, it will make a -tight joint with this member y f tachedto the farther end of lever 51 is a rod 'be inserted through hole 58 formed for that V 40.

yMeter shaft 31 bears against an upper bearing 38, held by frame 39, which is fastened to lugs 40 and 41 formed on ring 18 by screws 42 43. This frame also carries any well-known form of registering device 44, to which may be attached a member 45 for holdin the gear 44, .which makes contactrwith t Ve ,wo-rm (not,shown)...on shaftl in the well-known manner.

To counter-balance4 the upward thrust of also act as a shipping device to prevent the loss of mercury when the meter vis transported from one place to another, I employ a weight 46, which surrounds the shaft and normally is held in 'position by friction against the shaft. This weight has a gasket 48 on its lower face and a stuffing box 47, so that when it is lowered against the upper and prevent the escape of mercury. lVeight play the two arms of a bifurcated lever 51, supported by a member 52 by means of pivot 53, upon which the lever rotates, member 52 being fastened to the base in any suitable manner, such as by rivets 52. Pivotally at- 54, which is threaded at its lower end so as to thread into a nut 55 movable within afixed member 56, and having al nut 55 screwed upon its u per end to prevent withrom member. 56. Nut 57 is screwed onthe lower end of member 54 in its lower end, so that a screw driver may purpose, in order to rotate the nut 55 and thusmove the shipping device up and down.-

The operation of my meter is then as follows :-Current isled through the conductors, so as to pass from one edge of the meter armature to the other, thus producing a torque between the armature and the field produced by the magnet, causing the armature to rotate in the well-known manner. If it be desired to alter the calibration of the meter the retaining member surrounding the armature may be revolved, thus displacing the plane of the conductors and altering the meter torque.

If it is desired to ship the meter the nut 55 is`turned to the left, which will cause the bifurcated end of tlielever partially surrounding the shipping device to move downward and press weight 46 down, so as to make a tight join-t with the top of the member filling the interior of the meter armature and surrounding the shaft, and thus prevent the escape of mercury. 'When it is desired to operate the meter, nut 55 is turned in the reverse direction, thus raising the weight, and after it is raised the desired amount the nut is given a few turns in the rst-described direction, thus causing the lever to move out of contact'with the weightand prevent any frictional errors from this' source.

lVhile I have Shown a certain form of construction in which my invention may be car` iriedout, I do notdimit myself to this form shaped armature revoluble in mercury bctween the poles of the. magnet, a magnetic member substantially filling the interior of the armature, coiiductois leading current to diainetrically opposite edges of the armature, and a retaining member rigidly attached to the magnetic member and t-lie conductors and revolubly adjustable about the armature axis.

2. In a mercury meter, a magnet, a cupshaped armature revoluble in mercury between tlie poles of the magnet, a magnetic member substantially filling the interior of tlie armature, conductors leading current to the armature on either side of it in a diametral plane normally parallel to the flux of the magnet, and a retaining member sur'- rouiiding the armature, rigidly attached l'to the magnetic member and tlieconductors, and revolubly adjustable about the armature axis.

3. In a mercury meter, a U-shaped magnet, a cup-shaped armature revoluble in mercury between the poles of the magnet, a magnetic member substantially filling the interior of the arinatui'e, an insulating cover attached to the magnetic member and convductors attached to. the cover leading current to opposite edges of the armature and displaceableabout the meter axis.

4. In a mercury meter,I a U-shaped magnet, a cup-shaped armature with longitudinal slots in its edge revoluble in mercury between the poles of the magnet, a magnetic member substantially filling the interior of the armature, conductors-leading current to diainetrically opposite edges of the armature, rigidly attached to the magnetic meinber and a non-magnetic retaining ineiiibei rigidly attached to magnetic member and the conductors and revolubly adjustable about the armature axis.

5. In a mercury meter, a magnet, a cupsliaped aiinaturev attached to a shaft near its lower end revoluble in mercury between the poles of the magnet, a lower bearing for t-lie armature shaft, ainagnetic member substantially filling the interior of the armature, conductors leading current to opposite edges of the armature, and a retaining member surrounding the armature, rigidly attached to the magnetic member and the conductors, carrying the lower bearing for the armature shaft, and revoluble about the armature axis between the poles of the magnet.

6. In a mercury meter, a U-shaped magnet, a cup-shaped armature revoluble in mercury between the poles of the magnet, a retaining member surrounding the armature revolubly adjustable about the armature axis between the poles of the magnet, means attached to the poles of the magnet for supporting the retaining member, an insulating member covering the retaining member and rigidly fastenedI thereto, a magnetic mem ber substantially filling the interior-of the armature rigidly 'attached to the insulating member, and conductors rigidly attached to the insulating member leading current to opposite edges of the armature.

7. In a mercury meter, a U-shaped magnet, a cup-shaped armature with slotted edges revoluble in mercury between the poles lof the magnet, a shaft attached to the armature near its lower end, a ring attached to upper side ofthe pole pieces, a non-magnetic retaining member surrounding the armature between the magnet poles revolubly adjustable, a flange attached to the upper edge of the armature resting on the ring, a bearing for the'lower end of the meter shaft carried by the retaining member, an insulating covercovering the top of the retaining member rigidly fastened thereto and inclosing the armature, a magnetic member substantially filling the interior of the armature attached to the cover, conductors rigidly attached to the cover making contact with the mercury above diametrically opposite oints on the edge of the armature, means fiir rotating the retaining member with the conductors about an axis substantially the same Y as the armature axis and means for preventing such rotation.

8. In a mercury meter, a shipping device comprising a wei ht surrounding the arma ture, a bifurcate lever partially surrounding the weight and normally out of contact with it, a fixed member, a nut movable within the fixed member, a rod pivotally attached to an end of the lever and threading into the nut for raising and lowering the lever.

In witnesswhereof, I have hereunto set my hand this sixth day of April, 1908.

WILLIAM H. PRATT. Witnesses z Jol-1N A. MoMANUs, Jr., CHARLES A. BARNARD. 

